Cerebrospinal flud (CSF), thyrotropin releasing hormone (TRH), CSF-vasopressin (AVP), plasma-AVP, CSF-osmolality, plasma-osmolality, CSF-adrenaline (A) and -noradrenaline (NA) were measured in psychiatric patients and controls. Psychiatric patients were classified according to ICD-9 and grouped into endogenous depression, non-endogenous depression, mania and schizophrenia. The depressive groups were classified according to the Newcastle Rating Scale for Depression 1965. Severity of disease was quantified by BRMES, BRMS and BPRS. No difference in CSF-TRH levels was seen among the different diagnostic groups and controls. A positive correlation between CSF-TRH and CSF-A was demonstrated. CSF-AVP concentrations were significantly lowered in both endogenous and non-endogenous depression; no correlation with CSF-A or -NA was seen. Neither did any difference between plasma levels of AVP, plasma-osmolality or CSF-osmolality appear among the groups investigated.